This ancient caterpillar-like worm wore a suit of armor made of net-like plates.
In short: Long before modern animals dominated the seafloor, a strange creature called Microdictyon roamed the Cambrian oceans. This lobopodian worm featured ten pairs of tube-like legs and nine pairs of mysterious, netted sclerite plates. Scientists once mistook these isolated plates for sponges or echinoderms before discovering the complete animal in China.
Microdictyon, meaning small net in Greek, was an extinct lobopodian worm that lived during the Cambrian period. While its sclerite plates have been found globally since their first discovery in England in 1975, complete soft-bodied fossils are rare, appearing primarily in the Chengjiang Lagerstätte of Yunnan, China. These fossils reveal an elongate, caterpillar-like body reaching up to 77 millimetres in length, covered in fine annulations and small papillae. The creature lacked eyes, jaws, or complex appendages, suggesting a simple, conserved body plan.
The animal's most defining features were its nine pairs of subcircular, convex sclerite plates. These plates, characterized by a hexagonal mesh of hollow pits and mushroom-shaped nodes, were once the subject of intense scientific debate. Some researchers hypothesized they functioned as compound eyes, though this theory is now widely rejected. Current consensus favors the idea that these plates served as defensive armor or sites for muscle attachment. The plates were not static; evidence suggests the animal underwent a unique, asynchronous moulting process, where new plates formed beneath the old ones in a biphasic sequence similar to modern isopods.
Microdictyon was an epibenthic walker, using its clawed, lobopodous limbs to navigate the seafloor. Its claws were likely adapted for grabbing or climbing rather than walking on soft mud. Researchers often find Microdictyon fossils associated with other organisms like Eldonia or Cricocosmia, suggesting it may have been a scavenger or predator that interacted with these animals. Today, paleontologists recognize 11 valid species of Microdictyon, though many more remain in open nomenclature as researchers continue to classify isolated plates found in Cambrian deposits across the world, from Australia to North America.
Opens the Intellect+ feed with this card first. Swipe up for the next one.
Sources
- Summary by Intellect · source: Microdictyon
To cite this card, link to https://intellectplus.co.uk/app/nature-microdictyon.
How we source, check and correct cards: Editorial standards.
General information, not professional advice. Spotted an error? Flag the card or see corrections and complaints.
Intellect Plus is a visual educational discovery platform for exploring fascinating facts and ideas. Brain Food, Not Brain Rot. What is Intellect Plus?
Related
More in Bilateria, others · More in Nature · Latest · A–Z · All topics
